An eMBMS (enhanced Multimedia Broadcast/Multicast Service, enhanced Multimedia Broadcast/Multicast Service) is a broadcast technology used in LTE (Long Term Evolution, Long Term Evolution). In the eMBMS, a system defines a multimedia broadcast single frequency network (Multimedia Broadcast Single Frequency Network, MBSFN) area, that is, an MBSFN area. The MBSFN area includes multiple synchronized eNodeBs (evolved NodeB, evolved NodeB), and the eNodeBs in the same MBSFN no longer generate interference between themselves when sending same MBMS service data.
Based on a deployment characteristic of a wireless network, one eMBMS network generally includes multiple MBSFN areas, and each MBSFN area includes multiple eNodeBs. Each eNodeB sends MBMS (Multicast and Broadcast Management System, multicast and broadcast management system) service data to one or more UEs (User Equipment, user equipment) in the same MBSFN area. In practical application, the eNodeB generally transmits MBMS service data in the form of a carrier. At a same moment, a peripheral UE located in the MBSFN area probably receives a carrier sent by an eNodeB in another peripheral MBSFN area. That is, in a process of transmitting or receiving MBMS service data, a UE in an MBSFN area may suffer interference from MBMS service data transmitted from a peripheral MBSFN area, or may suffer interference from MBMS service data transmitted or received by one or more other UEs in a same MBSFN area. To reduce and eliminate such interference, a method for randomizing interference between different UEs and between different MBSFN areas is introduced in the LTE, where MBMS service data transmitted or received by the UE is scrambled by using a scrambling sequence, so as to reduce or eliminate interference caused by the MBMS service data transmitted or received by another UE.
A common method used currently to avoid interference between different MBSFN areas is to scramble MBMS service data by using a pseudorandom sequence, which achieves a purpose of suppressing interference between MBSFN areas. In the prior art, an area identity or a radio timeslot slot number is used as a scrambling parameter of a scrambling sequence to generate the scrambling sequence.
Because the scrambling sequence is set according to the MBSFN area identity and the radio timeslot number, that is, the MBMS service data received by the UEs in different MBMS areas at different moments have different scrambling sequences, the interference generated when the UEs in different MBMS areas transmit or receive MBMS service data can be reduced.
In a process of implementing the present invention, it is found that the prior art has at least the following problem: In a same MBMS area, if an eNodeB sends same MBMS service data to multiple UEs simultaneously, because the MBMS service data is the same and scrambling sequences are also the same, no interference is generated between the MBMS service data transmitted or received by different UEs. However, in the same MBMS area, if the eNodeB sends multiple pieces of different MBMS service data simultaneously, because the MBMS service data is different but the scrambling sequences generated for the MBMS service data are the same, relatively great interference is still generated between the MBMS service data.